Exercise Training and Vitamin D Metabolism

Overview

The prevalence of Vitamin D deficiency is significantly higher in adults with overweight/obesity compared to those with normal body mass index (BMI). The "entrapment" of Vitamin D in adipose tissue due to impaired lipolytic stimulation and/or adipose tissue dysfunction has been proposed as the driving mechanism. Exercise training has been proposed as a promising strategy to increase mobilization of Vitamin D from adipose tissue, given its well described role in stimulating lipolysis. Indeed, a recent study revealed that participation in moderate-intensity cardiovascular type exercise over winter can mitigate the decline in 25-hydroxyvitamin D \[25(OH)D\] in adults with overweight/obesity, independent of weight loss. The aim of this study is to investigate the impact of hybrid-type high-intensity interval training over winter on vitamin D metabolism, in adults with overweight/obesity.

Thirty adults with overweight/obesity (both males and females) who will meet the inclusion criteria will be randomly assigned to either an Exercise group (n=15) or a Control group (n=15). The Exercise group will participate in three hybrid-type high-intensity interval training sessions per week over a 12-week period, while receiving a balanced diet. The Control group will receive a balanced diet but will not participate in exercise training. Both groups will provide a resting blood sample and undergo assessment of their body composition (via bioelectrical impedance analysis), daily dietary intake (via dietary recalls) and physical activity level (via accelerometry) at baseline (prior to intervention), 6 weeks and 12 weeks.